Proceedings of the Vertebrate Pest Conference

The 2019 rodent eradication on 1,455-ha Lord Howe Island was the second and largest attempted on a permanently inhabited island. With 350 residents, it presented numerous novel challenges, resulting in an operation best summarised in four words: Compromise, Commensal, Complexity, and Cost. A ground-based operation was conducted across the built-up portion of the island, some 300 ha, with aerial bait applied on forested higher ground (1,200 ha); brodifacoum was used exclusively for this attempted eradication. Initial community resistance and the presence of mice meant that almost 19,000 external bait stations were established within the Settlement, on a 10-m grid. The intensive grid was expected to result in numerous bait stations within rodents’ home ranges. An additional 3,500 internal bait stations were put in all buildings and 9,500 hand-broadcast points overlapped the aerial and bait station boundaries. Over 60 field staff were employed locally, from Australia and overseas, to run the toxic baiting operation for 5.3 months. On-going resistance from a small community group resulted in two legal challenges early in the operational stage, including one in the Australian Supreme Court. Additional complications included initial active opposition to private land access; unaccepted personnel by the private land owners; resistance to livestock removal requiring novel bait station infrastructure; possible significant bait loss to invertebrates; and a small proportion of rats apparently avoiding bait stations. A fundamental aim of future operations on inhabited islands should be that they are community-led, which is likely to take several years to mature to the operational stage. Eradication practitioners should prepare for a significantly more complex operation with a concomitant increase in resourcing and planning.